Information processing devices capable of performing TCP/IP communication have widely been used today as information processing devices having the communication function. Some of such information processing devices are provided with a function of restricting access to the device from external devices based on a restriction table containing IP (Internet Protocol) addresses regarding the permission of the access (IP addresses of devices to be permitted to access the information processing device) and IP addresses regarding the prohibition of the access (IP addresses of devices to be prohibited from accessing the information processing device. Since such an information processing device is capable of blocking unauthorized access from outside, illicit use of the information processing device by an outsider, wasting expendables (paper, ink, toner, etc. when the information processing device is a printer having the communication function) and disabling authorized users from using the device, can be prevented while also blocking malicious access attempting to cause trouble to the device, which is convenient for the authorized users of the device.
However, an information processing device of this type prohibits the access to the device according to the restriction table even when an IP address is erroneously registered in the restriction table, which can lead to prohibition of access from a management device which should originally be permitted to access the information processing device.
In a system in which an administrator or manager can make settings of the restriction table of the information processing device from a management device via a network, if the access to the information processing device from the management device is disabled due to an erroneous setting to the restriction table, the administrator can not make any more settings to the restriction table from the management device via the network. In such cases, the administrator has to change the settings of the restriction table by directly operating the information processing device, which is highly inconvenient.
Of course such trouble never occurs if the administrator never registers an erroneous IP address in the restriction table. However, in a system letting the administrator specify an IP address range regarding the permission or prohibition of the access to the information processing device, the administrator can sometimes fail to notice that the IP address of the management device is within a prohibiting IP address range. In a system that registers each of permitting IP addresses according to operation information representing key operations, etc. by the administrator, the administrator, being distracted by the IP address registration task regarding devices other than the management device, can forget to register the IP address of the management device.